This disclosure relates to headlamp aiming systems in vehicular manufacturing processes.
Current headlamp aiming systems and methods, involving photometric aimers, utilize standard greyscale CCD (charge-coupled device) cameras, which gauge a beam pattern obtained from a headlamp. One part of an ideal analysis of a beam pattern obtained from the headlamp includes detailed identification of portions of the beam pattern to enable an accurate demarcation of a transition region. Here, the transition region may particularly be categorized as a cut-off or threshold that classifies one portion of the beam pattern as dark, while the other portion as the actual headlamp image. In particular, the transition region may form an outline of the headlamp image.
The usage of CCD cameras in conventional application of aiming a headlamp are found to cause inconsistencies in determining transition regions, such as the ones mentioned above, as certain portions and details of the obtained beam pattern are observed to be lost when the headlamp is brightly lit. Moreover, inadequate details resulting from improper contrast ratios and poor image shadows provided by the employed CCD cameras add to these inconsistencies. Currently, greyscale images obtained through the CCD cameras are converted to a saturated black/white image via adjustments in image exposure, causing the beam pattern to appear inaccurately, further leading to restrictions in determining precise transitions regions within the beam pattern. Software employed along with such a headlamp aiming processes perform such conversions, providing only approximate values of the threshold or the cut-off region in the beam pattern, thereby restricting a user's ability to accurately differentiate between a dark region and an actual headlamp image. More so, the values, being approximate, are obtained on a linear scale, the linear scale being generally dissimilar to a scale based on perceptions of the headlamp image by a human eye. Aiming headlamps through scales that are similar to the scales based on human perception of the headlamp image are according to the standards defined by the FMVSS (Federal Motor Vehicle Safety Standards) as well.
Need exists therefore to employ headlamp aiming systems that accurately define shadows and transition regions within a beam pattern, relating closely to the perceptions of the headlamp image to the human eye, and also to the standards set by the FMVSS.